Electric switch



Patents Nov. ll, 1924.

Mrs

1; Pics.

CHESTER D. AINSWORTH, 0E WOLLASTOE, MASSACHUSETTS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO CONDIT ELECTRICAL MANUFACTURING COMPANY, A CORPORA- TION OF MASSACHUSETTS.

ELECTRIC SWITCH.

Application filed March as, 1921. Serial No. 456,319.

ing a rod extended through an aperture in the frame for connection with switch operatlng; mechanism disposed above the frame; The operating mechanism is usually of that type adapted to guide the switch, rod

for vertical movement in approximately a. straight line. parture from a straight line movement and therefore it is desirable: to provide a substantial clearance between the switch frame and the switch rod; or the aperture in the frameis substantially larger than the diameter of the rod. It sometimes happens that, due to circuit interruption, oil is expel led from the switch through this aperture and onto switch leads and surrounding objects.

An object of this invention is to provide means to close the aperture in the switch frame and yet permit the switch rod to move therein without undue restriction.

A further object of the invention'is to provide means to increase the speed of the movable switch member toward switch open position and thereby increase the currentinterrupting capacity of the switch.

A. further object is generally to improve the construction and operation of an electric switch.

The switch embodying the invention may have a relatively thin disc or plate which has aperture therein through which the switch rod is slidably received; and the rod adapted to fit closely within the aperture I to restrict thefiow of mi therethrough al though there will be suflicient clearance to permit free movement of the switch rod. Said plate is adapted to be of greater diameter than the aperture in the switch frame and is adapted to bepressed against tie under side or the switch trains over, and

There is usually a small declose, the aperture therein by a. spring which may be carried by and encircle the switch rod and press against an abutment thereof. Sa d spring tends to force the movable switch member toward'switch-open position and, when the switch operating mechanism is operated to open the switch, will accelerate the movement of the movable switch member toward open position.

Fig. l is a side elevation of a switch embodying the invention partly broken away to illustrate the structure.

Fig. 2 is a sectional detail of the aperture closing plate and spring.

Fig. 3 is a side elevation in detail of the switch rod, spring and plate in the switchopen position of the movable switch member.

Fig. a is a. plan section along lines l-d of Fig. 2.

As here shown, the switch chosen to illus' trate'the invention includes the removable oil receptacle 10 depending from the switch frame 11 which forms a cover for the oil receptacle 10. Stationary switch members 12 are carried by said frame and depend into the oil in the receptacle. The movable switch member includes the brush member 13 which is pivotally carried on the lower end of the insulating" rod 14, which latter is or may be formed of wood or similar material. A recess is formed in the upper end of said rod and a rod 15 of steel or equivalent and of relatively smaller diameter than said insulating rod is secured in said recess, as by the pin 16. Said rodis extended upwardly through the aperture 17 in the top of said switch frame and is pivotally suspended trom the lever 18 of switch operating mechanism disposed above the switch frame.

Said mechanism is of the type adapted to guide the top of said rod 15 for vertical movement in substantially a straight line. lit usuallyhappens, however, that the rod 15 is moved laterally an appreciable amount, as well as vertically. Consequently, the aperture 1? is made of substantially greater diameter than the diameter of the rod 15 to permit such lateral movementwithout altering the vertical disposition of said rod. Due to conditions within the switch caused by circuit interruption oil may be expelled from the switch through the aperture and thrown on switch leads and other surrounding objects and, if the oil is burning when expelled, disastrous tires may occur.

In carrying out the invention the switch rod 15 below the switch frame is provided with a relatively thin plate or disc 19 which. has an aperture therein through which the rod is passed; and said aperture is such that the rod is a close sliding tit therein, although not so tight as to bind. Said plate is wider than the aperture 17 and is adapted to be held against the under side of the switch frame over said aperture thereby to close it; and in this respect said plate serves the function of a valve. Preferably the edge of said plate is reflexed to form the downwardly extended side wall 19 within which to receive the end of coil compression spring 20 which is adapted to hold said plate against the switch frame Said spring 20 is disposed. on said rod l5 below the plate 19 and said plate is preferably secured to the spring by suitable means, For instance said. plate may have an aperture in its side wall 19 through which the reflexed end 20* of the spring may be extended and a pin 21 may extend from said side wall under a convolution of the spring Preferably said plate is somewhat loosely retained on the end of the spring so that it may be self-seating on the switci frame over the aperture and also so that it may move laterally in contact with switch frame as the switch rod is moved vertically. i

Said insulating rod 1a is formed wi" the reduced upper end-portion A over which the metal ferrule 22 is forced: Said ferrule is formed with an outwardly extended flange 22" on its lower end-per hiclia. is adapted to form an abutment lower end of said spring 16 disposed l rule. Preferably, however, a d' 23 interposed between the lower end said soring and said flange 22 I washe in of greater diameter than sa flange to provide increased bearing the spring When the switch is closet will be compressed and h .v against the inner :tace of the J over the aperture 17, thereby closing it, as illustrated in Fig. l. lVhen the switch open ating mechanism actuated to open switch the rod 15 will move d rd the plate 19 which will be switch frame. The effective 20 is preferably suc" will hold said plate 19 over the a e 1? until the movable switch member has moved dow ward suilicie circuit 811F641? the movable switch member or it may be arranged to permit the separation of said plate 19 and switch frame and the unoovering of the aperture 1? at some time during the latter part of the downward movement of the movable switch member. in this event the spring and plate will be moved upward to cover the aperture when the movable switch member is moved upward toward and before it arrives in switch closed position. I

It the plate is arranged to uncover the aperture 17 after the circuit has been opened by the switch it will also serve as a valve to retain an elevated gas pressure in the expansion space A above the oil in the switch during circuit interruption which may facilitate the quenching of the arc, assuming the switch to be otherwise unvented, or insulficiently vented, and relieve the pressure subsequent circuit interruption.

I claim:

1. An electric switch comprising an. oil receptacle, a switch frame comprising a. cover for said receptacle having a relatively large aperture therethrough adapted to receive a switch rod,'stationary switch members depending from said frame into said receptacle, switch operating mechanism disposed above said frame, a switch rod having upper portion of relatively small diameter extended through said. aperture and connected with said mechanism and a lower insulating portion increased diameter, and means carried by said rod below said switch frame adapted to cover 7 ture.

2. An electric switch ceptacle, switch fra for said receptacle he aperture 1 switch pending om said ceptacle, s itch op nosed also said Eran a cover large carried by c adapted r:

saio ape. "re,

3. An electr receptacle,

rec

* an. oil reill) said switch frame adapted to cover said aperture comprising a cover plate slidably received on and closely fitting said rod below said switch frame, and a spring carried by said rod below said plate adapted to press said plate ieldingly against said switch frame over t e aperture.

4. An electric switch comprising a switch frame having a relatively large aperture therein adapted to receive a sw tch rod, an oil receptacle depending from said frame, stationary switch members carried by said frame, operating mechanism disposed above said frame, a switch rod having an upper portion of relatively small diameter eX- tended through said aperture and connected with said mechanism and a lower insulating portion of increased diameter, and means to cover said aperture comprising, a plate of larger diameter than said aperture slidably received on and closely fitting said rod under the switch frame, said rod having an abutment below said plate, and a spring encircling said rod between said plate and abutment arranged to press said plate against the under side of said switch frame over the aperture. 1 5. An electric switch comprising an oil receptacle, a switch frame comprising a cover for said receptacle having a relatively large aperture therethrough adapted to receive a switch rod, stationary switch members depending from said frame into. said receptacle, switch operating mechanism disposed above said frame, a switch rod having an upper portion of relatively small diameter extended through said aperture and connected with said mechanism and a lower insulating portion of increased diameter, and means carried by said rod below said switch frame adapted to cover said aperture comprising a cover plate slidably received on and closely fitting said rod below said switch frame, and a spring carried by said rod below said plate adapted to press said plate yieldingly against said switch frame over the aperture in upper positions of said switch rod and permit said plate to uncover said aperture in lower positions of said switch rod.

6. An electric switch comprising an oil receptacle, a switch frame comprising a cover for said receptacle having a relatively large aperture therethrough adapted to receive a switch rod, stationary switch members depending from said frame into said receptacle, switch operating mechanism disposed above said frame, a switch rodjhaving a relatively large insulating lower rod and a relatively small upper rod connected with said lower rod and extended through said aperture and pivotally connected with said operating mechanism, and means to cover said aperture comprising a coil spring carried by said lowerrod and extended upwardly about said upper rod and a cover plate slidably received on and closely fitting said upper rod and supported on said spring adapted-to be pressed against said switch frame over and cover said aperture.

7. An electric switch comprising an oil receptacle, a switch frame comprising a cover for said receptacle having a relatively large aperture therethrough adapted to receive a switch rod, stationary switch members depending from said frame, into said receptacle, s witch operating mechanismdisposed above said frame, a' switch ,rod having a relatively large insulating lower rod and a relatively small upper metal rod inserted in the upper end of said insulating rod and extended through said aperture and pivotally connected with said switch operating mechanism, a ferrule having an out wardly extended flanged lower end received on the upper end of said insulating rod, a coil spring encircling said switch rod be low said frame having its lower end supported by the flanged end of said ferrule, and a cover plate carried by the upper end of said spring slidably received on and closely fitting saidbpper rod adapted to be pressed by said spring against the under side of said switch frame over the aperture.

8. An electric switch comprising an oil receptacle, a switch frame comprising a cover for said receptacle having a relatively large aperture therethrough adapted to receive a. switch rod, stationary switch members. depending from said frame into said receptacle, switch operating mechanism disposed above said frame, a switch rod having a relatively large insulating lower rod and arelativelysmall upper metal rod inserted in the upper end of said insulating rod and extended through said aperture and pivotally connected with said switch operating mechanism, a ferrule having an outwardly extended flanged lower end received on the upper end of said insulating rod, a disc having an aperture therein loosely received over and supported by the flanged end of said ferrule, a coil spring encircling said switch rod below said switch frame having its lower end supported by said disc, and a cover plate having an annular downturned edge received over the upper end of said spring having an aperture therein in which said upper rod is closely slidably re and suspended from said operating mechanism, said movable switch member comprising a brush member adapted to bridge said stationary switch members immersed in the oil in said receptacle and a switch rod extendedupwardly from said brush member through an aperture in said switch frame andpivotally connected with said operating mechanism, and means to accelerate the switch opening movement of said movable switch member comprising, a coil spring encircling and supported by said switch rod below said switch frame arrangedto press against the under side of said switch frame and move down with said switch rod to a position free from said frame in the open condition of the switch.

10. An electric switch comprising an oil.

receptacle, a switch frame forming a cover for said receptacle, stationary switch members carriedby said frame depending into said receptacle, switch operating mechanism carried externally by and disposed abovesaid frame, a movable switch member disposedwithin said receptacle and carried by and suspended from said operating mechanism, said movable switch member comprising a brush member adapted to bridge said stationary switch members immersed in the oil in said receptacle and a switch rod extended'upwardly from said brush member through an aperture in said switch frame and pivotally connected with said operating mechanism, and means to accelerate the switch-opening movement of said movable switch member comprising, a coil spring encircling and supported by said switch rod below said switch frame and a plate carried by the upper end of said spring having an aperture through which said switch rod is slidably extended, said spring arranged to exert a pressure on said switch rod in a direction toward switch-open position and move down with said switchrod to a position free from said frame when the switch is in open condition. I

11. An electric switch comprisin an enclosing casing adapted to contain 0i and an expansion space above the oil, stationary and movable switch members contained in said casing, said casing having a vent for the gas expansion space, and closing means for said vent adapted to close the vent when the switch is closed and open the vent when the .switch is open:

12. An electric switch comprising an enclosing casing adapted to contain oil and an expansion space above the oil, stationary and movable switch members contained in said casing, said casing having a vent for the gas expansion space, and closing means for said vent adapted to hold the vent closed during a movement of the movable switch member to interrupt the circuit, and open the vent.

after the circuit is interrupted.

13. An electric switch comprising an enclosing casing adapted to contain oil and an expansion space above the oil, stationary and movable switch members contained in said casing, said casing having a vent for the gas expansion space, and means controlled,by the movable switch member to control the opening and closing of said vent.

14. An electric switch comprisin an en closing casing adapted to contain oi and an expansion space above the oil, stationary and movable switch members containedin said casing, said casing having a vent for the gas expansion space, and means controlled by the movable switch member arranged to close the vent when the switch is closed, and open the vent when the movable switch member is near full switch-open position.

, 15.. An electric switch comprising an en-- closing casing adapted to contain oil and an expansion space above the oil, stationary and movable switch members contained in said casing, said casing having a vent for the gas expansion space, and means operated by the movable switch member to open and-close said vent. Y

16. In .an electric switch, a brush-supporting member comprising an insulating rod of substantial length and diameter having supporting means for a brush-member at its lower end and having an axially-disposed recess inits upper end, a metal rod of substantial length and reduced diameter having its lower end secured in the recess in said insulating rod, and a ferrule surrounding the upper end of said insulatin rod and the recess therein, and a pin passe through said ferrule and both rods. 7

17. In an electric switch, a brush-supporting rod-of insulating material having a reinforcing ferrule at the upper end thereof, said ferrule formed with a lower outstanding flange at the lower end thereof, a metal 

